XFS partition limited to 2TB [SOLVED]

mjs · Last edited by mjs on Tue Sep 04, 2007 8:01 am; edited 1 time in total

I have a fresh install of Gentoo with kernel-2.6.22-r5, 3Ware-12ML controller (12 500G drives), driver compiled as a module.

The problem I'm having is that I am able to create a 5.5TB GPT partition in parted, but when I create the FS using mkfs.xfs it is truncated to 2TB. If I run parted again, it says "Unable to open /dev/sdb - unrecognized disk label". I can create the label and partition again and format it as ext3 5TB without a problem.

In parted, typing in 'help mklabel', xfs is not listed as an option. Does parted not work with xfs? Is there some other option, I'd really rather use xfs.

Habbit · Posted: Sat Sep 01, 2007 10:55 pm Post subject:

The version of parted shipped with the 2007.0 installation (mini) cd fully supports GPT, I myself have just made a gpt setup on a laptop. The fact that you are able to create & format an ext3 partition > 2TB shows it. It's probably XFS who can't handle huge partitions, but I can't confirm this nor point the blame to xfs itself or just its current implementation in linux.

The second error could come if you install GRUB 2 (my version was 1.95 CVS 20070829) and then run parted again. As grub installs its code on the first sector (the GPT-provided MBR guard showing a full-drive partition), your GPT partition table won't be damaged at all, and the Linux kernel will correctly detect the partitions if you compile it with GPT support, but parted will no longer identify the drive as gpt, forcing you to recreate the whole partition scheme should you ever want to modify it. Not good u_u... The only solution I know for the moment if you have a PC BIOS + GPT arrangement is to either never repartiton or install grub on a separate drive.

Also, when configuring GRUB, remember that you need to tell it to preload its GPT module, like this:

Habbit · Posted: Sat Sep 01, 2007 10:58 pm Post subject: Re: XFS partition limited to 2TB

mjs · Posted: Sat Sep 01, 2007 11:01 pm Post subject:

I didn't mention it, but the mbr is on a separate disk grub has never been used against the 3ware array.

The command I used to create the xfs fs was simply: 'mkfs.xfs /dev/sdb1' There is only one large partition.

mjs · Posted: Sun Sep 02, 2007 12:38 am Post subject:

Update:

I've discovered that even if I create an ext3 FS, it is mountable as is an xfs partition, but neither are mountable after a reboot. However unlike xfs, the ext3 partition is still recognizable by parted.

I also tried a smaller 1TB partition in ext3 and xfs with the same results; mountble and usable, until reboot.

This same problem also occurs on an identical server.

Rob1n · Posted: Sun Sep 02, 2007 10:28 am Post subject:

If it's a 32-bit system, do you have the Large Block Device support enabled in the kernel? XFS should be able to support up to 8EiB so I suspect the problems's at a lower level.

mjs · Posted: Sun Sep 02, 2007 6:07 pm Post subject:

Yes, thats enabled.

The problem appears to be two fold, the two 2TB limitation and also that the partitions disappear after a reboot regardless of their size or format.

mjs · Posted: Tue Sep 04, 2007 8:01 am Post subject:

Forgot to enable EFI support in the kernel. :oops:

This resolved both the 2TB limitation and the partition getting borked upon rebooot. I had this same problem about a year ago with another server, but for the life of me, could not remember what it was in the kernel config until tonight.